1. Field
The present disclosure relates to compositions, kits, and methods for isolating vesicles.
2. Description of the Related Art
Microvesicles are small membranous vesicles that exist in or are secreted from various types of cells. Microvesicles secreted from cells include: (i) exosomes, vesicles having a diameter of 30 to 100 nm that originate from cells; (ii) ectosomes (also called shedding microvesicles (SMVs)), vesicles that are released directly from plasma membranes and have a diameter of 50 to 1000 nm; and (iii) apoptotic blebs, vesicles secreted from dying cells that have a diameter of 50 to 5000 nm.
Using an electron microscope, it has been confirmed that exosomes are not directly released from a plasma membrane, but rather originate from specific intracellular regions called multivesicular bodies (MVBs), with fuse with the plasma membrane and are then released into the extracellular environment as exosomes. Exosomes are secreted from various different cell types under both normal and pathologic states. Red blood cells, various kinds of immune cells (such as B-lymphocytes, T-lymphocytes, dendritic cells, blood platelets, and macrophages), and tumor cells produce and secrete exosomes.
Microvesicles may contain microRNAs (miRNAs), which may be used to identify the status of cells or organisms. The status may be a disease, for example, cancer, hereditary diseases, heart diseases, or neuronal diseases, such as schizophrenia.
Existing methods of isolating microvesicles are performed by combining microvesicles and antibodies to immuno-capture microvesicles. Such methods may cause a bias due to masking of antibody recognition sites by conformational changes of a protein, microvesicle heterogeneity, protein interactions, etc. Furthermore, many existing methods require a complicated process, a high-cost apparatus, or a large sample volume.
Therefore, there is a need for improved methods of efficiently isolating microvesicles from a small amount of sample.